/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.phoenix.hbase.index;

import java.io.IOException;

import org.apache.phoenix.hbase.index.covered.update.ColumnReference;
import org.apache.phoenix.hbase.index.util.ImmutableBytesPtr;

public interface ValueGetter {

  /**
   * Get the most recent (largest timestamp) for the given column reference
   * @param ref to match against an underlying key value. Uses the passed object to match the
   *          keyValue via {@link ColumnReference#matches}
   * @return the stored value for the given {@link ColumnReference}, or <tt>null</tt> if no value is
   *         present.
   * @throws IOException if there is an error accessing the underlying data storage
   */
  public ImmutableBytesPtr getLatestValue(ColumnReference ref) throws IOException;
  
  public byte[] getRowKey();
}